How can I change the Kotlin compiler version on IntelliJ?

Question

In IntelliJ you can set the target Java version like this:

Unfortunately I don't see a place where I can do the same for Kotlin. This makes it not possible for me to use Quasar-Kotlin. I want to switch to M14 even though I have 1.0 beta installed. How can I change back?

After changing the build.gradle file back to M14 I am greeted with compilation errors in my project.

My build.gradle: https://gist.github.com/Jire/5b517fd767ad498bc18f

Carmelacarmelia

Please note that Quasar 0.7.4-SNAPSHOT (available on SonaType snapshots) supports 1.0 beta now. – Homoiousian

@Homoiousian yes, I opened the issue. Thank you! :) – Carmelacarmelia

Answer 1

Go to Intellij Preferences -> Build, Execution, Deployment -> Kotlin Compiler. Update Language version and Api version to the one you wish.

(You can also use cmd + shift + A and type Kotlin Compiler to get to this preference)

Saul

This should be the accepted answer.IMHO no. of upvotes proof of the same. – Geilich

Answer 2

Precondition:

The compiler bundled to Kotlin plugin (IDE) must be greater or equal than external compiler (project) used for building modules. So update Intellij IDEA to be compatible with the most up-to-date plugins.

Help > Check for Updates

Note: If you do not have the most updated version in Language and API version you will not be able to see the latest version of the plugin.

---

1- Install a new version of the compiler

• Languages & Frameworks > Kotlin

1. Check version: 1.3.61
2. Update channel: Early Access Preview 1.4x and press Check again
3. A new version 1.4-M3-xxx is available and press Install

• Invalidate Caches & Restart

• Observe in Languages & Frameworks > Kotlin that:

You have the latest version of the plugin installed.

• Build, Execution, Deployment > Compiler > Kotlin Compiler

1. Language and API version: Change from 1.2 To Latest stable 1.4-M3 (if the Latest stable 1.4-M3 version do not appear, so update the IDE)

Finally, check version in Project Settings > Modules > Module SDK > Kotlin SDK: 1.4-M3

2- Update compiler version in project

I recommend is to synchronize gradle with a non-existent version in order to clean the external libraries. This is because it could happen that our libraries continue to use the old version of the compiler after updating.

1. For example: change from 1.4-M3 to 1.4.20-M1

build.gradle.kts

plugins {
    kotlin("jvm") version "1.4-M3" apply false 
}

2. It is important to synchronize with a wrong version like X to clean the external libraries with which we would get the following message.

build.gradle.kts

plugins {
    kotlin("jvm") version "X" apply false 
}

3. Then we define and synchronize with the new version.

build.gradle.kts

plugins {
    kotlin("jvm") version "1.4.20-M1" apply false 
}

GL

Kotlin versions

Clink

Answer 3

You can't do this at the moment. Building your project in IntelliJ IDEA always uses the version of the Kotlin compiler bundled with the plugin, regardless of what your build.gradle file says. If you need to downgrade to M14, you need to install the M14 version of the plugin.

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How can I downgrade to the M14 version of the plugin? – Carmelacarmelia

I have v1.0.0-beta of the plugin installed and I am able to run his build.gradle without any problems. – Procreate

To downgrade you'd have to manually install the plugin right? I wonder if I can build and you cant due to the gradle cache mentioned in your output? Maybe Yole can provide more insight. – Procreate

Answer 4

The kotlin versions are defined in your build.gradle file.

See the following example :

build.gradle

Procreate

This is what I thought however I had changed the version to the latest M14 and it no longer will compile. build.gradle seems to specify the library version of Kotlin rather than the compiler. My build.gradle: gist.github.com/Jire/5b517fd767ad498bc18f – Carmelacarmelia

Updated original question with image of build attempt. – Carmelacarmelia

Yes, I am using the latest IntelliJ EAP and Kotlin plugin. – Carmelacarmelia

Try syncing gradle, gradle clean and if all else, deleting your build directory? – Procreate

Tried and it did not work. @Advertisement says that it's not possible yet and that I'd have to downgrade to the M14 version. – Carmelacarmelia

Answer 5

File -> Settings -> Build, Execution & Deployment -> Kotlin Compiler.

You should get something like in this image, and here you can change the version of Kotlin Compiler

Precession